We deveoled a device for automatically sampling substances liberated from the isolated lingual epithelium containing taste buds during repetitive taste stimulations. The device consists of three part : (1) Chamber for isolating the mucosal side from the basolateral side of the lingual epithelium ; (2) Programming and driving apparatus for repeated stimulation of the mucosal side with taste stimuli and deparate perfusion of the basolateral side with normal Tyrode solution. The number and duration of stimulations are programd ; (3) Sampling apparatus for tanspoting the solution containing substances liberated from the epithelium into the sample cups, which are cooled down up to-20ﾟC.Using this device, we detected two peaks of peptide-like substances by a high performance liquid chromatography (HPLC) in the sample liberated from rat lingual epithelium during gustatory stimulations. Two peaks detected in the sample botained from rat are roughly consistent with the peaks for Met-enkephalin
… Moreand CCK8, respectively. Secretion of serotonin which is observed in only type III taste bud cells was also detected during salt and acid stimulations. These results suggest that the automatic sampling device for substances liberated from living epithelial preparation developed here is useful for sampling, identification and quantification of the physiologically active substances under the physiological condition.On the other hand, using liposome with an artificial lipid, D_<14>DPC enabled us to directly extract membrane proteins from the lingual epithelial tissue. Using this technique, it was evident that the protein in the extracting membrane with liposome containting D_<14>DPC represents a high affinity to L-alanine. The gustatory neural responses to amino acids were suppressed by the liposomal treatment with D_<14>DPC of the tongue surface, but were not affected by the liposomal teatment without D_<14>DPC.Therefore, we concluded that the liposomal treatment with D_<14>DPC of the tongue epithelium in a powerful technique to extract the membrane proteins which have high affinity to tastants. Less